Hi guys, I'm after picking your brains, my '90 is running ok but at low revs when creeping along it is slightly lumpy, it feels like it is missing or choking as you slowly accelerate. There is no black smoke, the plugs are fairly new, the carbs have been cleaned out and sync'ed. Am I missing something obvious?
The problem is not serious, just chuffin annoying, if you roll into a slow corner as you pull out of it, for a split second it feels like the bike is going to "fall" into the corner!
Over 2500 rpm its fine and runs like a dream. I have been ironing out teething problems on this bike for a few months (since buying it) and hopefully this is the last of them. The problem has always been there I think but has been masked by the other problems,now they have gone it seems to show up more.

 

Sorry to hear about your probs mate , you said plugs are new , have you checked for a nice strong spark from each one ? If not maybe the leads . Have you checked the air filter/fuel filter for dirt /blockages . I'm no expert but that's where I'd start (if you haven't checked these already)

If the weather was better I'd suggest you take a trip to Brighton and we could try swapping a few parts around as we have virtually the same bike . Maybe the summer if its not sorted by then.

Good Luck!!

 

If you have a timing light, make sure the ignition is advancing.

 

Sounds like you're having a slight problem in the transition from slow speed circut to high speed in one or more carbs. Two potential problems. One, you might have a slight build up of varnish in one or more slow jets causing a lean condition before the mains take over, Or, two, the springs that sit on top of the slide have lost some tention and the slide/needles are coming up just a hair fast. I'd replace/clean the slow jets as a fist step. Go to a paint store and get some methylene chloride (paint stripper) and soak the jets overnight. If you use streight methylene chloride you wont attack the brass jets, but it will go after rubber so be careful.

 

I think the jet suggestion may be spot on. I had a similar problem after installing a V&H exhaust. Iinstalled larger jets and that problem was solved. So...maybe cleaning the jets?

 

Thanks guys, the jets were in the back of my mind but its good to ask you lot just incase you had seen the problem before, when it warms up a bit (snow on sunday) I will have them out

 

Before you start pulling the carbs around again, there are some rubber seals on the sides. If you place your fingers over then when the bike is at tickover and the revs increase then you know that these seals are dry. Place some vaseline over them to help lubricate them and repeat process untill they soften. Good luck

 

Handy little hint about the Vaseline. I have always had similar problems but not as bad as sawnee. I can never get my old girl to idle dead smooth or progress from pilot jets to main sweetly. Possibly a simple & easy fix.

 

Cheers for the tip collector, can you explain where these rubbers are?